bus: fsl-mc: pause the MC firmware when unloading

Pause the MC firmware when unloading the driver so that it doesn't
crash in certain scenarios, such as kexec.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Link: https://lore.kernel.org/r/20210715140718.8513-6-laurentiu.tudor@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 41861ca..e5b4830 100644 (file)
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -1207,6 +1207,16 @@ static int fsl_mc_bus_remove(struct platform_device *pdev)
 
        bus_unregister_notifier(&fsl_mc_bus_type, &fsl_mc_nb);
 
+       if (mc->fsl_mc_regs) {
+               /*
+                * Pause the MC firmware so that it doesn't crash in certain
+                * scenarios, such as kexec.
+                */
+               writel(readl(mc->fsl_mc_regs + FSL_MC_GCR1) |
+                      (GCR1_P1_STOP | GCR1_P2_STOP),
+                      mc->fsl_mc_regs + FSL_MC_GCR1);
+       }
+
        return 0;
 }